Spark arrester



May 24, 1932. s pso 1 ,859,804

SPARK ARRESTER Filed June 4, 1931 2 Sheets-Sheet 1 3mm! [mac Jz'npsozz May 24, 1932. 1 SIMPSON SPARK ARRESTER Filed June 4. 1931 2 Sheets-Sh et 2 gwvvnto'o [mac Jain won Patented May 24, 1932 UNITED STATES PATENT OFFICE ISAAC SIMPSON, OF WILMERDING, PENNSYLVANIA, ASSIGNOR F ONE-HALF TO 7 FREDERIC E. LYFORD, 0F WAVERLY, PENNSYLVANIA SPARK ARRESTER Application filed June 4, 1931. Serial No. 542,128.

The invention relates to spark arresters and has as an object the provision of a device of this character that will be self-cleanmg.

It is a further object of the invention to provide a spark arrester wherein cinders too large to pass through the screen will bebroken up by friction with the screen due to movement of the cinders themselves or of the in screen.

It is a further object .of the invention to provide a spark arrester having ample screen surface to pass the smoke without unduly restricting the draft through the firebox; 7

Further objects of the invention will appear from the following description when read in connection with the accompanying drawings showing an illustrative embodiment of the invention and wherein Fig. 1 is a detail vertical section through the front end of a boiler equipped with the invention, the screen and a portion of the smoke stack being shown in vertical section;

Fig. 2 is a horizontal section on line 22 of Fig. 1; and

Figs. 8 and 4 are vertical transverse sections on lines 33 and 4:4= respectively of Fig. 1.

As shown the device is applied to a locomotive boiler, the shell of the boiler being shown at 10, and a smoke stack at 11 having the inward downwardly flared extension 12 terminating at 13 above the lower inner surface of the shell. A door is shown at 14L for access to the interior of the smoke chamber and a second door 15 is shown for access to I the exhaust nozzle. An exhaust pot is shown at 16 having an exhaust nozzle 17 of any Well known form. v

In accordance with the invention a screen is shown at 18 which surrounds the smoke stack extension 12 in spaced relation thereto and is rigidly secured at its lower edge as at 19 to the shell 10. The screen 18 is shown as extending forwardly to the front plate 20 of the boiler shell. The portion 18 may be, and preferably is, placed upon an angle such as shown at its rear and the forwardly extending portions running parallel with the. axis of the shell are also shown as placed upon a like angle. Obviously the entire wall of the screen 18 may be placed vertical or the side extensions thereof may be horizontal or substantially so. 7

The upper edge of the screen 18 is shown as rigidly secured to a plate 21, which entirely surrounds the stack extension 12 and is rigidly secured thereto. The space between the front edge of the plate 21 and the front plate 20 of the boiler shell is shown as closed by a substantially horizontal screen 22. This screen is shown as secured at its ends to straps 23, 24, which are rigidly secured to the upper edges of the forward extensions of the screen 18. The screen 22 is thus so supported as to be allowed to vibrate vertically due to the pulsations of the exhaust through nozzle 17, which vibratory action is depended upon to clear the screen of cinders and to comminute cinders too large to pass through the screen;

To support the screen when stepped upon by workmen entering the door 1 1, there are shown brackets 25 26 which are spaced below the screen sufficiently to not interfere with its vibratory action and yet to support the screen from undue distortion. It is obvious that the vibratory screen 22 may be supported at its edges and mayvibrate by deflection longitudinally thereof. The spring action in any screen material is found to be sufficient when acted upon by the pulsating effect of the exhaust to cause vibration sufiicient to'clear the screen. Cinders drawn against the portion 18 of the, screen will drop to the bottom of the shell and will then again be drawn against the screen repeatedly. until comminuted to a size to allow passage through the screen and escape through the stack.

While the screen 22 is shown as in a plane surface and substantially horizontal, it is obvious that this portion of the screen may be placed at an angle to the horizontal either transversely or longitudinally or at any slop e from the center both ways towards its ends as desired. 7

l/Iinor changesmay be made-in the physical embodiment of the invention within the scope of the appended claims without departing from the spirit thereof.

I claim:

1. A spark arrester comprising, in combination, a smoke stack extending intg a smoke chamber and rearwardly spaced from a closed end thereof, an exhaust nozzle projecting into said stack extension, a screen closing the space between said extension and the wall of said chamber rearwardly and laterally of the extension and a substantially horizontal screen spaced from the bottomof the chamber and closing the space between said extension and the front end of the chamber, the central portion of said last named screen being marginally free and adapted to vibrate under the pulsating effect of steam passing through said nozzle.

2. A spark arrester comprising, in combination, a smoke stack extending into a smoke chamber, an exhaust nozzle projecting into said extension, a substantially horizontal screen closing a portion of the space between said extension and a wall of said chamber, said screen being partially free at edges thereof whereby it is mounted to vibrate under influence of pulsations of steam through said nozzle.

3. A spark arrester comprising, in combination, a smoke stack extending into a smoke chamber, an exhaust nozzle projecting into said extension, a substantially horizontal screen closing a portion of the space between said extension and a wall of said chamber, said screen rigidly supported at two opposite edges and being partially free at edges thereof whereby it is free to vibrate between said first edges under influence of pulsations of steam passing through said nozzle.

4. A spark arrester comprising, in combination, a smoke stack extendinginto a smoke chamber, an exhaust nozzle projecting into said extension, a substantially horizontal screen closing a portion of the space between said extension and a wall of said chamber, said screen rigidly supported at two opposite edges and being partially free at its other edges whereby it is free to vibrate between said first edges under influence of pulsations of steam passing through said nozzle, and rigid means projecting below and in normally spaced relation to the remaining edges to prevent undue downward flexure and especially to support the screen when stepped upon by workmen.

5. A spark arrester comprising, in combination, a smoke stack extension having its lower end disposed in a smoke chamber, an exhaust nozzle projecting into said smoke stack extension, a screen partially surrounding said smoke stack extension and having an edge in contact with the wall of said chamber, a generally horizontal plate and screen member at the top of the screen completing the closure of the space between said extension and said wall, said plate surrounding the stack extension above its lower end, straps between the plate and adjacent end wall of the smoke chamber to which the screen member is attached, said screen member being-partially free-:at edges thereof whereby it ZlSl'IlOllIltGCl-atOVlbI'fltG by its resilience under the pulsating effect of steam passing through said nozzle.

ISAAC SIMPSON. 

